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Posts Made By: Ron Oehlert

December 16, 2012 07:41 PM Forum: Telescope Making

Mirror clips

Posted By Ron Oehlert

For any size mirror, the simplest & easiest to construct is an over-sized flat triangle of wood under the mirror. The cut-off *points* of the triangle are the mounting points & can be supported parallel to the optical axis by bolts & nuts (like *legs* protruding behind & attched to rear of mirror box). Springs over the bolts under the board work well with smaller mirrors or nuts on each side of board with bolt passing thru allows mechanical push-pull alignment that remains aligned when screwed down snug despite travel vibration (use washers under the nuts to spread load across more wood). Anchor the bolts to either the mirror box or cell board with adjustment provided at the other ends of bolts; which end depends on what is convenient to your situation/arrangement. Size the wood thickness & bolts to the mirror; if they look flimsy they are & likewise if they look sturdy enough. An index mark on the mirrors' side (or back, if view holes are cut into mirror board & mirror box) along with a corresponding mark on the cell allows returning to collimated position if travel rotates the mirror in it's cell. Heavy-duty felt furnature pads may be used to support the mirror (underneath) & inverted L-shaped blocks of wood standing on the *point* ends serve as both retaining clip & side supports (padded with pieces of furnature pads). Precision construction is un-neccessary since the mirror should Not be clamped tight to cell, but remain loose-fitting. The larger the mirror, the more underneath support pads used. I used such a home-made push-pull cell for decades & never needed to re-collimate unless the mirror was removed.

June 1, 2013 05:11 PM Forum: After Dark

HOO NELLY! Aurora time!

Posted By Ron Oehlert

Hi Andy, cloudy here in central Kansas all night (about 37 degrees north) but I have observed red spikes like that from my location in the past.

June 14, 2013 11:31 AM Forum: After Dark

Mounting bolts for Meade LX200 12''

Posted By Ron Oehlert

I realize you are seeking a specific Kit or such with all necessary hardware included, but if all else fails, take your wedge & tripod to a local Hardware store & trial-fit for thread size. Preferred Brass or Stainless bolts are weather-resistant at slight cost increase over Cadmium-plated steel hardware, but otherwise function no better; chain-affiliated Hardware stores carry all three types in a large selection of thread sizes & lengths, Metric & American. Rural locations are typically no exception to local availability & even Nylon or brass thumb screws for eyepiece retention are readily found there. Inquire of a clerk for assistance if need be.

July 21, 2013 07:54 AM Forum: AstroMart FAQ

Going from Sponsor to Member?

Posted By Ron Oehlert

The Purple Level is the basic $15/annual membership which also gives you one month on the Sponsor list. Longer inclusion on the Sponsor list (i.e. 3 months, 6 months, or for life) is obtained with the higher levels of Annual membership. Sponsors see new classified ads immediately while members have a 4-hour delay after their posting before viewing new ads. Select Account Menu from the My Account box on left side of screen, then scroll to the very bottom of your Account Menu & select Renew Support Level from the Support Box for the options. Since you are a Purple member now, simply renew at that basic $15 level. You'll then also be on the Sponsor list again for one month but after that time period you'll again be a basic member for the rest of the year or until you decide to up-grade your Sponsor level.

July 31, 2013 09:22 AM Forum: TeleVue

Thumb screws to mount Clamshell Ring to Telepod He

Posted By Ron Oehlert

Your local Hardware store may have what you need.

August 2, 2013 01:38 PM Forum: After Dark

spare bolts and nuts for Meade 16

Posted By Ron Oehlert

Have you tried the same size but with a different thread pitch; i.e. NC (coarse), NF (fine), or Metric (I do not know which of those your stated thread pitch is, but two remain to be trialed)?

August 6, 2013 06:14 AM Forum: Deep Sky Observing

Televue tv-102

Posted By Ron Oehlert

You will be limited in what you can see by the rather small 4" aperture & with much detail beyond capability, but under a dark sky site and as a low-power wide-field scanner of the Milky Way is should be thrilling; *Scotty* Houston also viewed with a 10" reflector, mentioning same often in his former S&T column. Under dark rural Kansas skies of limiting magnitude 6 (dimmest star readily seen with the un-aided eye) where the Milky Way is a prominant lane across the sky, IMO 6" aperture is minimum for viewing brighter DSO's in some detail, but an 8" provides double the light grasp & it is under these skies that Scotty used his 10" reflector. Under urban Kansas skies of about limiting magnitude 3 (still a smallish 10K-20K population city surrounded by rural land & at least 75 or more miles distant from larger metro areas) & where the milky way can barely be detected as a sky-haze, a 6" is un-suitable for DSO's other than to claim you found it. But here, an 8" begins to showcase the brightest DSO's. So it comes down to what you actually want to see (in all their visual glory or merely/barely found) and where you intend to observe from. Perhaps post the limiting magnitude from your primary observing spot? I'd think your location in Minnisota should be similar to or even better than mine in Kansas, at least that is how I recall the skies of Northern Wisconsin when I visited in younger days. As a recomendation for what I imagine your sky is like, an 8" f/6 Dob gathers a lot of light yet is also easily portable. Such as instrument could compliment the low-power DSO capability of the TV, or supplant it. BTW, my 1st scope was a 2.4" (60mm) f/8 achromat and it thrilled me.

September 10, 2013 10:19 AM Forum: Refractors

Refractor below zero

Posted By Ron Oehlert

And when bringing the scope back indoors after a cold nights' observing session, reverse the process, covering lens/scope while still outside before moving it inside. My problem in such frigid near zero conditions was unequal metal contractions/expansions; dissimilar metals in contact can cause one to break. So perhaps reduce screw tension adjustments from their normal indoor or temperate climate settings.

December 9, 2013 10:10 AM Forum: Eyepieces

Re: HELP, experience with Meade 4000, yellow and w

Posted By Ron Oehlert

Meades' 20th aniversary 1992 print catalog has a series 4000 5-element rubber grip/rubber eyecup plossl set like the non-rubber originals & their 1997 General Catalog has the now 4-element series 4000 set; both rubberized sets outwardly appear identical. The Japan rubberized Super Wide Angles have similar lens groupings to the originals with some internal lens curve differences as revealed from dissassembly; those changes yield a sharper edge-of-field at the expense of less sharp on-axis & closer back focus (eye relief) for the rubber SWA set. During this same period all series 4000 (#140 2X Triplet) & series 3000 Barlows (#123 2X, #127 2X-3X variable, & #126 2X shorty) were also of Japan mfg & marked as such.

December 26, 2013 12:53 AM Forum: Eyepieces

Education from University Optics please...

Posted By Ron Oehlert

Hi Andy, that U-number is an individual Serial number ala camera lenses, so it is the original Konig. And it's from UO's Professional Series of Ortho eyepieces which at 1st were only single-coated. Like camera lenses of the period, they also came in individual leather cases. The UO Pros were identical to the GOC Saturn-logo eyepieces sold by Telescopics; the Telescopics' 16.3mm was called the Galoc. And the UO Pros have Japan MOP (or just MOP on the 28mm Ortho) stamped underneath the edge of their top caps, like Meades' Research Grade line (all of the RG Wide Fields were of 1-2-1 Konig construction & not true Erfles). With top caps removed, there is no discernable difference from the UO Pros or the Telescopics eyepieces; they are identical. Later UO offered an NS-stickered flat-top Konig line in several focal lengths followed by volcano-top Circle-Tee Konigs or Konig II's, but in long-focus scopes these are inferior to the original serial-numbered version in sharpness & FOV. I either still have or have had several complete sets of all of these. When I'm back home after the Holidays I can check S&T ads for dates if you want.